A child pulls a wagon by the handle along a flat sidewalk.

1. The problem statement, all variables and given/known data
A child pulls a trolley by the handle along a ﬂat sidewalk. She exerts a force of 80.0 N at an angle of 30.0° above the horizontal while she moves the wagon 12 m forward. The force of friction on the trolley is 34 N.

2. Relevant equations
(a) Calculate the mechanical work done by the child on the trolley.
(b) Calculate the total work done on the trolley